(1) Field of Invention--Water Decontamination
(2) Description of Prior Art
A major problem in removing unwanted contamination due to spills from our free-flowing streams and creeks is the nature of the many different kinds of contaminants which can occur and already are present in the streams. These contaminants range in size from large floating leaves and twigs, to smaller yet heavier plant seeds, to silt, rocks and solids, to partially decomposed organic matter, to floating oil and to chemicals in suspension or solution.
Previous systems for the separation of contaminants from flumes and streams have employed a variety of screens, ramps, weirs, separators, filters and skimmers in different combinations depending on the contaminant to be removed. Some of such systems as shown in the following patents:
______________________________________ Group I - Flumes with Weirs and Filters Xander 671,685 Apr. 9, 1901 210-170 Heller 1,477,660 Mar. 6, 1923 210-162 Cavenah et al 2,844,255 July 22, 1958 210-170 Kinne 3,282,430 Nov. 1, 1966 210-170 Jones 3,850,807 Nov. 26, 1974 210-170 Group II - Flumes with Ramps and Filters Blake 636,747 Nov. 14, 1899 210-162 Church 799,829 Sept. 19, 1905 210-162 Yordy 1,290,470 Jan. 7, 1919 210-154 Van Duzer 2,669,197 Feb. 16, 1954 210-162 Wait 2,055,808 Sept. 29, 1936 210-170 Group III - Flume with Ramp and Weir Michel et al 3,817,383 June 18, 1974 210-305 Group IV - Flumes with Upflow Non-Clogging Separators Cowley 95,089 Sept. 21, 1869 210-154 Durbrow 802,183 Oct. 17, 1905 210-154 Durbrow 832,245 Oct. 2, 1906 210-170 Hurst 1,451,394 Apr. 10, 1923 210-162 Perkins 3,854,291 Dec. 17, 1974 210-170 ______________________________________
A system designed to remove oil from the surface of a stream, such as shown in the above listed Jones U.S. Pat. No. 3,850,807, will, by its very nature, allow heavier particulate matter and dissolved chemicals to remain in the stream. Similarly, screens set up to trap large particulate matter, such as leaves, twigs, paper, or fine mesh sack to strain out weed seeds, such as shown in the above listed Kinne U.S. Pat. No. 3,282,430, will have little effect on chemical pollutants.
As the screen mesh gets finer or when filters using activated charcoal or other chemical reactants are employed, another problem develops. These filters can become clogged by larger particulate matter very rapidly, resulting in inefficient filtering, loss of time in cleaning the filter, and additional expense.
Often complex filtration systems require a permanent structure, usually constructed of masonry or a similar material, such as shown in the above listed patents to Xander U.S. Pat. No. 671,685, Wait U.S. Pat. No. 2,055,808, and Perkins U.S. Pat. No. 3,854,291, in which time for construction is long and the expense involved is high.